- Novel isopentenyl flavonoid compound and preparation method and application thereof
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The invention discloses a novel isopentenyl flavonoid compound which is prepared by the following steps: (1) taking herba epimedii, crushing or not crushing, extracting with a solvent for 1-3 times, extracting for 0.2-3 hours each time, combining extracting solutions obtained by two times, and concentrating the extracting solutions under reduced pressure to obtain extract, and (2) adding water into the extract to prepare a suspension, carrying out gradient elution separation on the suspension by using macroporous resin, carrying out gradient elution separation by using an ODS column, and finally purifying the isopentenyl flavonoid compound by using an efficient preparative liquid phase. The isopentenyl flavonoid compound can be converted into icariin under the conditions of heating, acid treatment, enzyme treatment, alkali treatment and the like. The method is simple and convenient to operate, and the prepared compound has high purity.
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Paragraph 0037-0040
(2020/11/10)
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- Ep7GT, a glycosyltransferase with sugar donor flexibility from: Epimedium pseudowushanense, catalyzes the 7- O -glycosylation of baohuoside
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Icariin (1a), a 7-O-glycosylated flavonoid glycoside, is recognized as the major pharmacologically active ingredient of Epimedium plants, which have been used in traditional Chinese medicine for thousands of years. However, no glycosyltransferase (GT) responsible for the 7-O-glycosylation of flavonoids has been identified from Epimedium plants to date. Herein, a GT, Ep7GT, was identified from E. pseudowushanense B. L. Guo, which can regiospecifically transfer a glucose moiety to baohuoside (1) at 7-OH to form icariin (1a). Ep7GT showed a rare broad donor substrate spectrum, including UDP-glucose, UDP-xylose, UDP-N-acetylglucosamine, UDP-rhamnose, UDP-galactose, UDP-glucuronic acid and TDP-glucose. Moreover, two new derivatives of icariin (1a), 7-O-β-d-[2-(acetylamino)-2-deoxy-glucopyranosyl]-baohuoside (1b) and 7-O-β-d-xylosyl-baohuoside (1c), were biosynthesized by using Ep7GT in vitro. Engineered Escherichia coli harbouring Ep7GT was constructed, and 10.1 μg mL-1 icariin (1a) was yielded by whole-cell biotransformation with baohuoside (1) as the substrate. The present work not only characterizes the GT responsible for the 7-O-glycosylation in the biosynthesis of icariin in Epimedium plants, but also indicates the significant potential of an enzymatic approach for the production of glycosylated baohuoside derivatives with different sugar moieties. What's more, these findings also provide a promising alternative for producing natural/unnatural bioactive flavonoid glycosides by metabolic engineering.
- Feng, Keping,Chen, Ridao,Xie, Kebo,Chen, Dawei,Liu, Jimei,Du, Wenyu,Yang, Lin,Dai, Jungui
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supporting information
p. 8106 - 8114
(2019/09/19)
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- Synthesis of icariin from kaempferol through regioselective methylation and para-Claisen - Cope rearrangement
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The hemisynthesis of the naturally occurring bioactive flavonoid glycoside icariin (1) has been accomplished in eleven steps with 7% overall yield from kaempferol. The 4?-OH methylation of kaempferol, the 8-prenylation of 3-O-methoxymethyl-4?-O-methyl-5- O-prenyl-7-O-benzylkaempferol (8) via para-Claisen-Cope rearrangement catalyzed by Eu(fod)3 in the presence of NaHCO3 , and the glycosylation of icaritin (3) are the key steps.
- Mei, Qinggang,Wang, Chun,Zhao, Zhigang,Yuan, Weicheng,Zhang, Guolin
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p. 1220 - 1225
(2015/08/18)
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